Method for placing cast-in-place concrete pile, placing management system, and placing management program

Abstract

To place concrete according to the position of a flow resistance part provided in a pile while suppressing the amount of highly fluid concrete used.SOLUTION: In a method for driving a cast-in-place concrete pile 1, a determination function including a variable related to a property of high fluidity concrete and a variable related to a structure of the cast-in-place concrete pile is used to set a switching depth Dx between concrete 100 used in a lower portion of the cast-in-place concrete pile 1 and high fluidity concrete having higher fluidity than the concrete 100 used in the lower portion below a core reinforcing bar 14 which is a flow resistance portion in which fluidity of the concrete 100 decreases.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a method for casting cast-in-place concrete piles, a casting management system, and a casting management program. [Background technology]

[0002] When pouring cast-in-place concrete piles, it is common to pour standard ready-mixed concrete (hereafter referred to as concrete) with a slump value of, for example, 21 cm, from the bottom of the pile upward. To prevent the stabilizing liquid from mixing into the concrete, the tip of the tremie pipe is kept embedded in the poured concrete.

[0003] The pile head is more prone to poor concrete filling than other areas due to the large amount of reinforcing bars and steel materials concentrated there. Figure 8 shows an example in which an assembly member 13 is attached to a reinforcing bar cage 12 installed in a pile hole 11. The assembly member 13 is a spacer, a reinforcing ring, or the like. By pouring concrete 100 using a tremie pipe 19, the stabilizing liquid 102 is replaced by the concrete 100, and the pouring surface 110 of the concrete 100 rises.

[0004] At this time, as shown in Figure 8(a), the assembly member 13 may reduce the upward flow of the concrete 100. As a result, as shown in Figure 8(b), a contaminated area 103 where the concrete 100 has mixed with the stabilizing solution 102 may occur around the assembly member 13. This contaminated area 103 can become a weak point in the concrete pile. Furthermore, when a cast-in-place concrete pile has a core reinforcing bar 14, the concrete 100 is likely to be poorly filled.

[0005] One of the most effective measures to deal with insufficient filling is to use high-fluidity concrete. For example, Patent Document 1 proposes overflowing high-fluidity concrete from above the steel pipe, allowing the high-fluidity concrete to flow between the steel pipe and the inner surface of the pile hole, replacing the stabilizing liquid with the high-fluidity concrete. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-48910 Summary of the Invention [Problem to be solved by the invention]

[0007] However, high-flow concrete is more expensive than standard concrete. Using high-flow concrete for the entire concrete pile improves filling ability, but it also increases costs. In addition, because the location of components that cause flow resistance to the concrete varies from pile to pile, it is difficult to predict the occurrence of low-filling areas, such as the mixed area 103, where the concrete has low filling ability. [Means for solving the problem]

[0008] The present disclosure provides a method for casting a cast-in-place concrete pile, which uses calculation information including variables related to the properties of high-fluidity concrete and variables related to the structure of the cast-in-place concrete pile to calculate a depth that is the relative distance between a flow resistance portion where the fluidity of the concrete decreases and a switching depth at which to switch from the concrete to high-fluidity concrete, pours the concrete into a lower portion of the cast-in-place concrete pile, and switches from the concrete to high-fluidity concrete at the switching depth that is set below the flow resistance portion by the calculated depth.

[0009] The present disclosure provides a concrete pouring management system, in which a control unit executes a process of calculating a depth, which is the relative distance between a flow resistance portion where the fluidity of concrete decreases and a switching depth at which the concrete is switched to the high-fluidity concrete, using calculation information including variables related to the properties of the high-fluidity concrete and variables related to the structure of the cast-in-place concrete pile.

[0010] The present disclosure provides a pouring management program that causes a control unit to execute a process of calculating a depth, which is the relative distance between a flow resistance portion where the fluidity of concrete decreases and a switching depth at which the concrete is switched to the high-fluidity concrete, using calculation information including variables related to the properties of the high-fluidity concrete and variables related to the structure of the cast-in-place concrete pile. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to reduce the amount of high-flow concrete used while pouring concrete according to the position of the flow resistance part of the pile. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating the casting of a cast-in-place concrete pile in one embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of the concrete pouring management system of the same embodiment. [Figure 3] 10A and 10B are schematic diagrams showing a procedure for calculating a switching depth in the embodiment. [Figure 4] 10 is a conceptual diagram showing a flow of identifying a switching depth in the embodiment. FIG. [Figure 5] 10 is a flowchart showing a procedure for calculating a switching depth in the embodiment. [Figure 6] 10A and 10B are schematic diagrams illustrating the switching depth of the embodiment. [Figure 7] 10 is a flowchart showing the steps of the concrete pouring method of the same embodiment. [Figure 8] 1A and 1B are diagrams showing the state of concrete filling in a conventional pile head, where (a) shows the state where concrete is filled up to the bottom of the assembly member, and (b) shows the state where concrete is filled up to the top of the assembly member. DETAILED DESCRIPTION OF THE INVENTION

[0013] Below, we will explain the method for pouring cast-in-place concrete piles, the pouring management system, and the pouring management program. FIG. 1 shows an example of a cast-in-place concrete pile 1 during casting. A pile hole 11 is formed in the ground 104. A reinforcing bar cage 12 and a core reinforcing bar 14 are placed in the pile hole 11. The reinforcing bar cage 12 is located radially outward of the core reinforcing bar 14. The core reinforcing bar 14 is located in the radial center of the pile hole 11. The reinforcing bar cage 12 is provided with an assembly member (not shown) such as a spacer or a reinforcing ring.

[0014] In the cast-in-place concrete pile 1, concrete 100 (fresh concrete) with different fluidity is used in the lower part 16 and the upper part 17. Lower part concrete 101, which is concrete 100 with a controlled slump value, is poured into the lower part 16 via a tremie pipe 19. High-fluidity concrete 105, which has higher fluidity than the lower part concrete 101, is poured into the upper part 17 of the cast-in-place concrete pile 1 via a tremie pipe 19. The upper part 17 is the head of the pile where the core reinforcing bars 14 are located. In this way, by using high-fluidity concrete 105 only in the upper part 17 rather than using high-fluidity concrete 105 for the entire pile, costs can be reduced.

[0015] Furthermore, in the past, the presence of flow resistance areas caused steps to form on the top of the poured concrete, so more concrete 100 was poured at the lower part of the steps to reach the target top height. However, by using the high-flow concrete 105, there is no need to pour extra concrete 100.

[0016] In order to minimize the amount of high-fluidity concrete 105 used while maintaining good filling properties in the upper part 17, it is necessary to appropriately set the switching depth Dx of the lower part 16 and the upper part 17. However, since the configuration of each pile is different, if the switching depth Dx is made shallow and the amount of high-fluidity concrete 105 used is too small, there is a high possibility that low-filled areas will occur. Furthermore, if the switching depth Dx is made deep and the amount of high-fluidity concrete 105 used is too large, costs will increase. For this reason, in this embodiment, the information processing device 20 is used to set the switching depth Dx using a judgment function including multiple variables that contribute to filling properties.

[0017] 2 shows an example of the information processing device 20. In this embodiment, the information processing device 20 constitutes a pouring management system 15. The information processing device 20 is used by a builder or the like. The information processing device 20 is a multi-function phone (smartphone), a tablet terminal, a personal computer, etc. The information processing device 20 includes a processor 21, a storage device 22, a communication device 23, an input device 24, and a display device 25. These are connected via a system bus 26, etc. The processor 21 and the storage device 22 correspond to a control unit 27. Note that this hardware configuration is an example, and it is also possible to realize it using other hardware.

[0018] The processor 21 executes a program stored in the storage device 22 to function as a depth calculation unit 30 and a learning unit 31. The depth calculation unit 30 calculates the depth X using calculation information including variables related to the properties of the high-fluidity concrete 105 and variables related to the structure of the cast-in-place concrete pile 1. The depth X is the relative distance between the flow resistance portion where the fluidity of the concrete 100 decreases and the switching depth Dx at which the concrete 100 is switched to the high-fluidity concrete 105.

[0019] The depth calculation unit 30 also sets the switching depth Dx at a depth X below the flow resistance portion. The flow resistance portion is the reinforcing bar cage 12, the core reinforcing bar 14, an assembly member 13 (see FIG. 8) attached to the reinforcing bar cage 12, etc. In the example of FIG. 1, it is the core reinforcing bar 14. The flow resistance portion used to set the switching depth Dx is, among the reinforcing bars etc. placed in the cast-in-place concrete pile 1, one with small gaps between members (for example, between reinforcing bars), or one with the deepest depth at that position, etc.

[0020] The learning unit 31 calculates parameters of a judgment function for calculating the switching depth Dx using the past construction history. The storage device 22 stores calculation information 32 and pouring history information 33. The calculation information 32 and pouring history information 33 are one or more pieces of data, and are composed of structured data or unstructured data. They include a map (or graph) for determining the switching depth Dx and parameters of a judgment function used to determine the switching depth Dx. The pouring history information 33 includes sample data used for regression analysis of the parameters of the judgment function. The sample data includes design information and correct answer labels of cast-in-place concrete piles 1 that have been cast in the past. The correct answer labels are appropriate values ​​verified after casting for the switching depth Dx or the depth X used to set the switching depth Dx. The parameters of the judgment function are optimized using the pouring history information 33 and updated as necessary.

[0021] The following describes the hardware configuration of the information processing device 20. Examples of the processor 21 include a CPU, an MPU, and an NPU. The processor 21 can be configured as any of the following:

[0022] [1] One or more processors that operate according to a computer program (software). [2] One or more dedicated hardware circuits that perform at least some of the various processes [3] Circuits containing combinations of these The communication device 23 is an interface that establishes a communication path with other devices via a network (not shown) such as the Internet.

[0023] The storage device 22 (computer-readable medium) includes any available recording medium that can be accessed by a general-purpose or dedicated computer, such as RAM, ROM, or a hard disk. A concrete selection program is stored in the storage device 22. The input device 24 is a touch panel, mouse, keyboard, microphone, or the like. The display device 25 is a liquid crystal panel, an organic EL panel, or the like.

[0024] (Switching depth setting) Setting of the switching depth Dx will be described with reference to Figures 3 and 4. The switching depth Dx is set below the position of the flow resistance portion by a depth X. As shown in Figure 3, a judgment function 40 is used to calculate the depth X.

[0025] An example of the judgment function 40 is a logistic function with asymptotes at the upper and lower limits. For example, the judgment function 40 is expressed by the following mathematical formula (1). "ax" is a combination of multiple variables 41 with different units.

[0026]

number

[0027] Slump flow is a variable that indicates the fluidity of concrete 100, and is specified by the diameter of the spread of concrete that flows out when a slump cone filled with concrete 100 is pulled up. Slump is a variable that indicates the softness of concrete 100, and is the length that the top of a slump cone filled with concrete 100 drops down due to its own weight when it is pulled up.

[0028] As the flow resistance in the flow resistance section increases, it is preferable to deepen the switching depth Dx by increasing the depth X. This is because the lower concrete 101 is partially present near the switching depth Dx. In other words, if the high-fluidity concrete 105 is switched to at a depth close to the flow resistance section with high flow resistance, the partially present lower concrete 101 will slow down the filling of the flow resistance section. For this reason, if a flow resistance section with high flow resistance exists, the switching depth Dx is deepened so that when the high-fluidity concrete 105 poured into the pile hole 11 reaches the flow resistance section, the low-fluidity lower concrete 101 will not be present.

[0029] The density of reinforcing bars is the degree of concentration of reinforcing bars. The pile head where reinforcing bars are concentrated is difficult for the concrete 100 to pass through, and the flow resistance is high. For this reason, the judgment function 40 calculates a result such that the greater the density of reinforcing bars, the greater (deeper) the depth X becomes.

[0030] Furthermore, if the pile diameter is large, the flow distance from the opening of the tremie pipe 19 becomes longer. Therefore, the judgment function 40 calculates a result such that the depth X increases as the pile diameter increases. The strength is, for example, the design strength Fc, which is the compressive strength of concrete set in structural calculations. Concrete with a higher design strength Fc is more viscous and less likely to flow. For this reason, the judgment function 40 calculates a result in which the greater the strength, the greater the depth X.

[0031] Furthermore, if the slump value of the lower concrete 101 is large, the gradient of the pouring surface around the pile becomes larger. Therefore, the judgment function 40 calculates a result such that the depth X becomes larger as the slump value becomes larger. Furthermore, since the high-fluidity concrete 105 flows more easily as the slump flow value becomes larger, the judgment function 40 calculates a result such that the depth X becomes smaller (shallower) as the slump flow value becomes larger.

[0032] The depth calculation unit 30 identifies the depth X using the calculation result of the judgment function 40 and the map 50. The vertical axis of the map 50 is a value calculated by inputting the variable 41 into the judgment function 40. In the map 50, the coordinate of the vertical axis is divided into a plurality of ranges, and the depth X is determined in stages. The depth calculation unit 30 obtains the depth X associated with the range that includes the calculated value of the judgment function 40 from the map 50.

[0033] When calculating the depth X, the depth calculation unit 30 identifies the position of the flow resistance portion of the high-flow concrete 105 in the cast-in-place concrete pile 1. Then, the switching depth Dx is set at a position that is the depth X below the position of the bottom end of the flow resistance portion. In the example of FIG. 1, the flow resistance portion is the core reinforcing bar 14, and the switching depth Dx is set at a position that is the depth X below the position of the bottom end of the core reinforcing bar 14. The position of the bottom end of the core reinforcing bar 14 is expressed, for example, as the depth from the top end of the pile hole 11. In the case of a concrete pile that does not have a core reinforcing bar 14, the bottom end of the part where the reinforcement is overcrowded may be used as the reference from the perspective of the fluidity of the concrete 100. Alternatively, the assembly member 13 provided on the reinforcing bar cage 12 may be used as the reference.

[0034] FIG. 4 is a conceptual diagram illustrating the flow in which the learning unit 31 obtains the parameters of the judgment function 40 by regression analysis. The pouring history information 33 includes variables 41 and correct answer labels 42 as sample data. The pouring history information 33 is divided into training data 33A and verification data 33B. The learning unit 31 defines a linear regression model 43 for “ax”.

[0035] The linear regression model 43 is expressed by a formula such as "ax=β1x1+β2x2+β3x3+β4x4+β5x5." "x1" to "x5" are the variables 41. "β1" to "β5" are the partial regression coefficients (parameters) of "x1" to "x5." The linear regression model 43 may include a bias term "β0" that is not a coefficient of a variable.

[0036] The learning unit 31 trains the linear regression model 43 using training data 33A. After training, the learning unit 31 calculates the switching depth Dx or depth X using the verification data 33B and compares it with the correct label 42. For example, the learning unit 31 adjusts the partial regression coefficients "β1" to "β5" so as to reduce the error between the prediction result and the correct label 42 (step ST). In step ST of adjusting the partial regression coefficients, the learning unit 31 compares the output of the judgment function 40 with the correct label to adjust the partial regression coefficients.

[0037] When the pouring of one cast-in-place concrete pile 1 is completed, the data is added to the pouring history information 33. The learning unit 31 may perform a regression analysis when the pouring history information 33 is updated.

[0038] (Method of casting cast-in-place concrete piles) The steps of the method for placing the cast-in-place concrete pile 1 will be described with reference to FIGS. 5 shows the procedure for setting the switching depth Dx and the position of the tremie tube 19. The depth calculation unit 30 sets the switching depth Dx (step S1). As described above, the depth calculation unit 30 inputs the variable 41 into the exponent "ax=β1x1+β2x2+β3x3+β4x4+β5x5" of the judgment function 40 to calculate the depth X.

[0039] 6, the depth calculation unit 30 identifies the tip position D1, which is the lower end of the core reinforcing bar 14, and sets the switching depth Dx below the tip position D1 by the depth X. The depth calculation unit 30 outputs the set switching depth Dx to the display device 25.

[0040] Returning to FIG. 5, once the depth calculation unit 30 has set the switching depth Dx, it sets the tip position D2 of the tremie pipe 19 for pouring the high-flow concrete 105 (step S2). The tip position D2 is the position of the discharge outlet of the tremie pipe 19. As shown in FIG. 6, the depth calculation unit 30 sets the tip position D2 of the tremie pipe 19 a depth Y1 below the switching depth Dx. For example, the depth Y1 is "2 m". The depth calculation unit 30 outputs the set tip position D2 to the display device 25.

[0041] The depth calculation unit 30 also sets a tip position D3 of the tremie pipe 19 after the pouring surface of the high-fluidity concrete 105 has risen (step S3). For example, as shown in FIG. 6, when the pouring surface of the high-fluidity concrete 105 has risen to a position D4 that is higher than the switching depth Dx by a height H1, the tip position D2 of the tremie pipe 19 is switched to a tip position D3 that is higher than the tip position D2. For example, the depth calculation unit 30 sets the tip position D3 of the tremie pipe 19 to a depth Y2 below the switching depth Dx. For example, the depth Y2 is 1 m. The depth calculation unit 30 outputs the set tip position D3 to the display device 25.

[0042] With reference to FIG. 7, the pouring of the high-fluidity concrete 105 will be described. After checking the switching depth Dx and the tip positions D2 and D3 of the tremie pipe 19 set in step S1 using the information processing device 20, the builder pours the lower concrete 101 for the lower part 16 up to the switching depth Dx (step S10). Then, the builder sets the discharge port 19A of the tremie pipe 19 to the tip position D2 (step S11).

[0043] Next, the high-fluidity concrete 105 is poured through the tremie pipe 19 (step S12). As a result, the high-fluidity concrete 105 is poured onto the layer of lower concrete 101. The pouring surface of the high-fluidity concrete 105 rises as the amount of high-fluidity concrete 105 increases from the start of pouring.

[0044] When the pouring surface of the high-fluidity concrete 105 rises by a height H1 from the switching depth Dx and reaches a position D4, the discharge port 19A of the tremie pipe 19 is switched to the tip position D3 (step S13). Then, the high-fluidity concrete 105 is poured up to the top of the pile via the tremie pipe 19 (step S14). At this time, if the depth from the top of the pile to the switching depth Dx is equal to or greater than a predetermined distance (for example, 5 m), the discharge port 19A of the tremie pipe 19 may be adjusted by moving it upward as the pouring surface of the high-fluidity concrete 105 rises so that it does not become too deep relative to the pouring surface.

[0045] <Effects of the embodiment> As described above, according to the above embodiment, the following effects can be obtained. (1) The pouring management system 15 calculates the depth X using a judgment function 40 including variables 41 related to the properties of the concrete 100 and variables 41 related to the structure of the cast-in-place concrete pile 1, and sets the switching depth Dx to the depth X below the flow resistance portion. Therefore, it is possible to suppress the occurrence of low-filled portions where the concrete is poorly filled while suppressing the amount of high-flow concrete 105 used.

[0046] (2) The concentration of rebars at the pile head is used as one of the structural variables 41 of the cast-in-place concrete pile, and the greater the concentration of rebars, the greater the depth. Therefore, when the high-fluidity concrete 105 reaches the flow resistance portion, the bottom concrete 101 is not mixed into the high-fluidity concrete 105.

[0047] (3) The judgment function 40 is a logistic function having asymptote at the upper and lower limits, and the learning unit 31 optimizes the parameters included in the judgment function 40 based on the past casting history of the cast-in-place concrete pile 1. Therefore, an appropriate switching depth Dx can be set based on the casting history.

[0048] <Example of change> The above-described embodiment can be modified as follows: Each embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0049] In the above embodiment, the calculation information is the judgment function 40, but other than this, it may be a table associating variable values ​​with scores, a trained model, or the like. In the above embodiment, the flow resistance portion is the reinforcing bar cage 12, the core reinforcing bar 14, etc., but it may also be a portion related to the shape of the cast-in-place concrete pile 1. For example, the flow resistance portion may be a concave structure for forming a protrusion on the side surface of the pile.

[0050] In the above embodiment, the variables 41 are the density of the rebar, the strength, the pile diameter, the slump value of the concrete 100 in the lower portion 16, and the slump flow value of the concrete 100 in the upper portion 17, but at least one of these may be used. Also, instead of or in addition to these variables 41, variables related to the concrete 100, such as the water-cement ratio, the air content, and the fine aggregate ratio, and variables related to the structure of the cast-in-place concrete pile 1, such as the type of flow resistance portion, may be used. Variables related to the external environment, such as the season and temperature range, may also be used.

[0051] In the above embodiment, the pouring management system 15 may use the variable 41 to determine the properties or type of high-fluidity concrete 105 to be poured. For example, an appropriate slump flow value of the high-fluidity concrete 105 may be calculated depending on the density of the rebar. The more dense the rebar, the larger the slump flow value. The builder can select the high-fluidity concrete 105 based on the properties or type of the high-fluidity concrete 105 determined by the pouring management system 15.

[0052] In the above embodiment, when the pouring surface of the high-flow concrete 105 reaches position D4, the discharge outlet 19A of the tremie pipe 19 is switched to the tip position D3 (step S13), but the discharge outlet 19A can be switched as appropriate depending on various conditions such as the depth from the top of the pile to the switching depth Dx. [Explanation of symbols]

[0053] 1...cast-in-place concrete pile, 13...reinforced concrete cage as flow resistance part, 14...core reinforcing bar as flow resistance part, 15...pouring management system.

Claims

1. A method for driving a cast-in-place concrete pile, comprising: Using calculated information including variables related to the properties of the high-flow concrete and variables related to the structure of the cast-in-place concrete pile, calculate a depth that is the relative distance between a flow resistance portion where the fluidity of the concrete decreases and a switching depth at which the concrete is switched to the high-flow concrete; The concrete is poured into the bottom of the cast-in-place concrete pile, A method for pouring a cast-in-place concrete pile, in which the concrete is switched to the high-flow concrete at the switching depth set below the flow resistance portion by the calculated depth.

2. 2. A method for casting a cast-in-place concrete pile according to claim 1, wherein the concentration of reinforcing bars at the head of the pile is used as a variable related to the structure of the cast-in-place concrete pile, and the greater the concentration of reinforcing bars, the greater the depth.

3. The calculated information is a logistic function having upper and lower asymptote lines, The method for driving a cast-in-place concrete pile according to claim 1 , wherein parameters included in the logistic function are optimized based on a past driving history of the cast-in-place concrete pile.

4. A casting management system for cast-in-place concrete piles equipped with a control unit, The control unit A casting management system for cast-in-place concrete piles that uses calculation information including variables related to the properties of high-fluidity concrete and variables related to the structure of the cast-in-place concrete piles to perform a process of calculating the depth, which is the relative distance between the flow resistance area where the fluidity of the concrete decreases and the switching depth at which the concrete is switched to high-fluidity concrete.

5. A program for managing the placement of cast-in-place concrete piles, comprising: In the control section, Execute a process of calculating a depth, which is a relative distance between a flow resistance portion where the fluidity of the concrete decreases and a switching depth at which the concrete is switched to the high-fluidity concrete, using calculation information including variables related to the properties of the high-fluidity concrete and variables related to the structure of the cast-in-place concrete pile. A program for managing the placement of cast-in-place concrete piles.

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